PHP中的图像文件大小压缩答案

【问题标题】：Image file size compression in PHPPHP中的图像文件大小压缩
【发布时间】：2023-11-13 02:39:01
【问题描述】：

我已经研究过诸如此类的先前问题的答案，但我没有运气。我的代码工作正常，但它上传了原始文件大小，我想在不改变原始高度和宽度的情况下压缩文件大小（例如从 600kb 到至少 200kb）。我已经尝试过从同一问题给出的答案，但我得到的是缩略图大小（8.0kb），并且上传的图像变成了纯黑色图像。

请帮助我如何使用我目前拥有的图片上传代码来做到这一点。非常感谢！

$allowedExts = array("gif", "jpeg", "jpg", "png");
$temp = explode(".", $_FILES["file"]["name"]);
$extension = end($temp);

// this assumes that the upload form calls the form file field "file"
$name  = $_FILES["file"]["name"];
$type  = $_FILES["file"]["type"];
$size  = $_FILES["file"]["size"];
$tmp   = $_FILES["file"]["tmp_name"];
$error = $_FILES["file"]["error"];
$savepath = "gallery/";
$filelocation = $savepath.$name;
$newfilename = $savepath.$ign;

// Check image file dimensions first and then file size
list($width, $height) = getimagesize($tmp);

if($width > "800" || $height > "600") {
    echo "Error: Image size must be a maximum of 800 x 600 pixels.";
}
else if ($size > 500000) {
    echo "Error: Image file must be a maximum of 500KB only.";
}

// This won't upload if there was an error or if the file exists, hence the check
if (!file_exists($filelocation) && $error == 0) {
    $album = escape_sql(CleanUp($_POST['album']));
    $caption = escape_sql(CleanUp($_POST['caption']));
    $privacy = escape_sql(CleanUp($_POST['privacy']));

    // echo "The file $filename exists";
    // This will overwrite even if the file exists
    $temp = explode(".", $_FILES["file"]["name"]);
    $newfilename = "gallery/".$album."/".$ign.".".$extension;
    move_uploaded_file($tmp,$newfilename);

    date_default_timezone_set('Asia/Manila');
    $date = date('Y-m-d');
    $timestamp = strtotime($date);

    mysqli_query($connect, "INSERT INTO `gallery` (`id`,`ign`,`album`,`privacy`,`caption`,`filename`,`timestamp`) VALUES ('','$user','$album','$privacy','$caption','$newfilename','$date')");

    echo '<h1>My Photos &#10097; <i>Uploaded</i></h1>';
    echo '<p>Your photo has been uploaded successfully to the '.$album.' album.</p>';
}
else {
    unlink($filelocation);
    move_uploaded_file($tmp, $filelocation);

    echo '<h1>My Photos &#10097; <i>Error</i></h1>';
    echo '<p>An error has occurred and your photo was not uploaded to the gallery.';
}

【问题讨论】：

我在这里看不到任何尝试调整大小的代码...
查看这里以获得纯 php 解决方案。 *.com/a/12557415/5873008
@AlexHowansky，是的，没有，因为那是我拥有的原始代码。我不确定将调整大小的代码放在哪里，或者什么是正确的代码来调整大小。
有很多库可以让您轻松调整大小。

标签： php

【解决方案1】：

ffmpeg 通常对我来说很好，即使使用默认设置，

function compressImage(string $imageBinary):string{
$tmph=tmpfile();
$tmpf=stream_get_meta_data($tmph)['uri'];
file_put_contents($tmpf,$imageBinary);
system("ffmpeg -y -i ". escapeshellarg($tmpf). " " . escapeshellarg($tmpf.".jpg"));
$ret=file_get_contents($tmpf.".jpg");
fclose($tmph); // deletes the file, thanks to tmpfile()
unlink($tmpf.".jpg");
return $ret;
}

【讨论】：